Application of probiotics intestinal preparation combined with early enteral nutrition in perioperative period of laparoscopic rectal cancer radical proctectomy / 中国医师进修杂志

Objective:To study the safety and practicability of probiotics intestinal preparation combined with early enteral nutrition in perioperative period of laparoscopic rectal cancer radical proctectomy.Methods:The clinical data of 131 patients who underwent selective laparoscopic rectal cancer radical proctectomy in Shengjing Hospital of China Medical University from January to June 2018 were retrospectively analyzed. Among them, 80 patients received probiotics intestinal preparation combined with early enteral nutrition (experimental group), and 51 patients received traditional intestinal preparation and postoperative treatment (control group). The bleeding volume during operation, hospitalization expenses, first exhaust time, postoperative hospitalization time, indwelling catheter time and complications were compared between 2 groups.Results:The bleeding volume during operation, hospitalization expenses, postoperative hospitalization time in experimental group were significantly less than those in control group: (166.33 ± 15.18) ml vs. (226.47 ± 16.46) ml, (42 365 ± 3 921) yuan vs. (51 048 ± 4 772) yuan and (13.32 ± 1.03) d vs. (13.98 ± 1.29) d, and there were statistical differences ( P<0.01). There were no statistical difference in the first exhaust time, indwelling catheter time and incidence of complications between 2 groups ( P>0.05). Conclusions:The probiotics intestinal preparation combined with early enteral nutrition in perioperative period can reduce the hospitalization expenses and shorten the hospitalization time in patients undergoing laparoscopic rectal cancer radical proctectomy, which is safe and feasible.

Meta-analysis of the function of carbon nanoparticles use in the surgery of thyroid cancers / 国际外科学杂志

Objective:To systematically evaluate the role of nanocarbon in the surgical treatment of thyroid cancer.Method:Searched Pubmed database, Web of Science, Cochrane Library, CNKI database, Wanfang database and VIP database for researches related to nanocarbon and thyroid cancer. The search key words included nano carbon, nano-carbon, carbon nanoparticles, nano-carbon parathyroid negative imaging technique, thyroid neoplasms, thyroid cancer, thyroid carcinoma. And also manually retrieved article references. The search time was from the establishment of the database to March 10, 2020. Two researchers separately screened and sorted out the data, and evaluated the quality of the articles and evaluated the publication bias. Revman 5.3 was used for data analysis.Results:Twenty-six randomized controlled studies were included, with a total of 2291 patients, including 1149 in the test group and 1142 in the control group. The results showed that the postoperative complications rate of the test group using nanocarbon was significantly lower than that of the blank control group, and the differences were statistically significant, including the parathyroid erroneous excision rate ( OR=0.24, 95% CI: 0.16-0.34, P<0.001), the incidence of postoperative hypoparathyroidism ( OR=0.38, 95% CI: 0.28-0.52, P<0.001), the incidence of postoperative hypocalcemia ( OR=0.40, 95% CI: 0.30-0.54, P<0.001) and the recurrent laryngeal nerve injury rate ( OR=0.50, 95% CI: 0.31-0.81, P<0.001). Conclusion:The use of nanocarbon tracing technology during the operation can reduce the complications of thyroid cancer resection and is worthy of clinical use.

Mining hub genes related to liver cancer stage in TCGA database with weighted correlation network analysis method / 中国医师进修杂志

Objective@#Primary liver cancer is a kind of gastrointestinal malignant tumor with high morbidity and mortality. Early diagnosis is difficult, with postoperative high recurrence rate and high metastasis rate, poor prognosis, so it is particularly important to better understand the occurrence and development of liver cancer from the gene level, so as to provide theoretical basis for gene therapy or targeted drug therapy in the future.@*Methods@#TCGA database for liver cancer gene transcriptome data information and clinical phenotype information was downloaded, and R language edgeR package was used to standardize the transcriptome data. The log FC > 1, FDR < 0.01 gene was set to be expressing differences gene, and then the weighted correlation network analysis (WGCNA) methods was used to analyze the relationship between liver cancer stage (stage) and the differentially expressed genes to look for hub genes.@*Results@#Four hub genes related to tumor staging were identified (TPX2, HJURP, KIAA1524, SGO2). Kaplan-meier survival curve was drawn and it was found that their expression level was significantly correlated with patient survival time, and high expression level was an independent prognostic factor.@*Conclusions@#WGCNA method is used to mine the TCGA database information and find the hub genes related to tumor staging. The relationship between TPX2, HJURP, KIAA1524 and liver cancer has been reported in the literature, except SGO2. This study will provide important theoretical basis for the follow-up study of liver cancer.

Study on thermophysical properties and effect of lyoprotectants in freezing human hepatoma Hep-G cells / 生物医学工程学杂志

Cell freeze-drying can be divided into the freezing and drying processes. Mechanical damage caused by ice crystals and damage from solute during freezing shall not be ignored and lyoprotectants are commonly used to reduce those damages on cells. In order to study the mechanism of lyoprotectants to protect cells and determine an optimal lyoprotectant formula, the thermophysical properties and percentage of unfrozen water of different lyoprotectants in freezing were investigated with differential scanning calorimeter (DSC). The survival rate indicated by trypan blue exclusion test and cell-attachment rate after 24 h using different lyoprotectants to freeze hepatoma Hep-G cells were measured after cell cryopreservation. The results show that 40% (W/V) PVP + 10% (V/V) glycerol + 15% (V/V) fetal bovine serum + 20% (W/V) trehalose formula of lyoprotectant demonstrate the best effect in protecting cells during freezing, for cell-attachment rate after 24 h is 44.56% ± 2.73%. In conclusion, the formula of lyoprotectant mentioned above can effectively protect cells.

Analysis of clinical effect on 19 cases of inguinal hernia treated by laparoscopic totally extraperitoneal repair / 国际外科学杂志

Objective To investigate the effect of laparoscopic total extraperitoneal tension-free hernia repair (TEP) in the treatment of inguinal hernia with absorbable biological mesh.Methods A retrospective analysis of the clinical data of 19 patients with inguinal hernia with biological mesh was performed from September 2015 to September 2016 in Shengjing Hospital of China Medical University.The average operative time,average incision pain time,average postoperative venting time,average hospital stay,average operative cost,and long-term chronic pain,postoperative complications,and recurrence rate were observed.Results All the 19 patients were successfully operated.The average operation time was (35.0 ± 4.0) min,the average incision pain time was (1.5 ± 0.6) d,and the average postoperative venting time was (1.5 ± 1.2) d.The average hospital stay was (4.5 ±0.9) d,the average surgery cost was (23 534.6 ± 1 259.9) yuan.Two patients developed swelling of the scrotum after surgery,and one patient developed postoperative fat liquefaction.All patients were followed up for 1 year by telephone,with no recurrence,no serious complications,and chronic pain discomfort.Conclusions The application of absorbable biopsy TEP is a good and reliable way to treat inguinal hernia.Postoperative patients have mild pain and low complication rate.There is no recurrence in recent follow-up,and the short-term effect is satisfactory.It is a reliable method for the treatment of inguinal hernia.The cost is high,and can be selected according to age and individual needs.

Brain Regional Homogeneity Changes in Cirrhotic Patients with or without Hepatic Encephalopathy Revealed by Multi-Frequency Bands Analysis Based on Resting-State Functional MRI

OBJECTIVE: To investigate brain regional homogeneity (ReHo) changes of multiple sub-frequency bands in cirrhotic patients with or without hepatic encephalopathy using resting-state functional MRI. MATERIALS AND METHODS: This study recruited 46 cirrhotic patients without clinical hepatic encephalopathy (noHE), 38 cirrhotic patients with clinical hepatic encephalopathy (HE), and 37 healthy volunteers. ReHo differences were analyzed in slow-5 (0.010−0.027 Hz), slow-4 (0.027−0.073 Hz), and slow-3 (0.073−0.198 Hz) bands. Routine analysis of (0.010−0.080 Hz) band was used as a benchmark. Associations of abnormal ReHo values in each frequency band with neuropsychological scores and blood ammonia level were analyzed. Pattern classification analyses were conducted to determine whether ReHo differences in each band could differentiate the three groups of subjects (patients with or without hepatic encephalopathy and healthy controls). RESULTS: Compared to routine analysis, more differences between HE and noHE were observed in slow-5 and slow-4 bands (p 12, overall corrected p < 0.05). Sub-frequency band analysis also showed that ReHo abnormalities were frequency-dependent (overall corrected p < 0.05). In addition, ReHo abnormalities in each sub-band were correlated with blood ammonia level and neuropsychological scores, especially in the left inferior parietal lobe (overall corrected p < 0.05 for all frequency bands). Pattern classification analysis demonstrated that ReHo differences in lower slow-5 and slow-4 bands (both p < 0.05) and higher slow-3 band could differentiate the three groups (p < 0.05). Compared to routine analysis, ReHo features in slow-4 band obtained better classification accuracy (89%). CONCLUSION: Cirrhotic patients showed frequency-dependent changes in ReHo. Sub-frequency band analysis is important for understanding HE and clinical monitoring.

Laparoscopic treatment of gallbladder fistula: a retrospective clinical analysis of 24 cases / 中国医师进修杂志

Objective To explore the experience and efficacy of laparoscopic diagnosis and treatment of internal gallbladder fistula (IGF). Methods The clinical data of 24 cases of IGF treated by laparoscopic exploration/surgery were retrospectively analyzed in Shengjing Hospital of China Medical University from January 2012 to January 2018. Results All the 24 patients had underwent laparoscopic exploration and were confirmed as IGF. Among these patients, 16 cases had cholecystoduodenal fistula, 3 cases had cholecystocolic fistula, 3 cases had cholecystogastric fistula, and 2 cases had cholecystocholedo fistula (Mirizzi syndrome). All patients underwent cholecystectomy, and patients with common bile duct stones underwent common bile duct exploration and T tube drainage. Treatment of internal fistula including:duodenal fistula repair (16 cases), colon fistula repair (3 cases), gastric fistula repair (3 cases), duodenal fistula repair and gastrectomy (1 case), and Roux-en-Y cholangiojejunostomy (1 case). Eleven cases were performed laparoscopically (45.8％);13 cases were converted to open surgery (54.2％). Postoperatively, 2 patients experienced mild bile leakage and healed after active drainage for 2 months, and the rest recovered well. After 6 months of follow- up, no complications such as gastrointestinal fistula, obstruction, or stenosis occurred. Conclusions The clinical manifestations of gallbladder fistula generally lack specificity, so that preoperative diagnosis is difficult. IGF is hardly to self- heal, and surgical treatment is still the mainstay for treatment. For appropriate situation, experienced surgeons with the developed laparoscopic techniques are reliable treatment for IGF.

Study of isolation efficiency of new islet isolation solution for mouse islets / 器官移植

Objective To investigate the isolation and protective effect of a new islet purification solution (IPS)-Optiprep solution on the islet in mouse models. Methods The digested pancreatic islets were divided into the IPS and UW groups according to the islet volume. The pancreatic islets were isolated by the continuous gradient density centrifugation using IPS-Optiprep or UW-Optiprep solutions. The purification efficiency and isolated islet activity of purification solution were compared between two groups. The diabetic mouse models were successfully induced and randomly assigned into three groups. In the experimental group (n=10), the mice received pancreatic islet transplantation using islets isolated and purified by the IPS-Optiprep solution. In the control group (n=10), the mice underwent pancreatic islet transplantation using islets isolated and purified by the UW-Optiprep solution. In the sham surgery group (n=5), the mice merely underwent surgery without pancreatic islet transplantation. Postoperative blood glucose levels were detected and compared among three groups. The blood glucose levels of intraperitoneal glucose tolerance test at postoperative 21 d were statistically compared between the experimental and control groups. The cost of the preparation of two isolation solutions was also compared. Results Compared with the UW group, the islet equivalent (IEQ), islet purity, recovery rate and islet integrity were significantly higher in the IPS group. Islet morphological observation revealed that the islet membrane was complete and the islet diameter in the IPS group was considerably larger than that in the UW group. The activity of purified islets in the UW group was significantly higher than that in the IPS group [(88±5)% vs. (84±3)%, P<0.01]. Compared with the UW-Optiprep solution, identical in vivo islet function was obtained in the IPS-Optiprep solution.The cost of IPS-Optiprep solution was significantly less than that of the UW-Optiprep solution. Conclusions The new IPS-Optiprep solution yields higher islet isolation efficiency, purification, integrity and recovery rate and significantly reduces the purification cost compared with the UW-Optiprep solution. Nevertheless, IPS-Optiprep solution exerts a less protective effect on the activity of islet cells, which is probably correlated with the high islet integrity and the endotoxin in the IPS-Optiprep solution.

Association between TNFα-308 polymorphism and inflammatony bowel disease susceptibility in Chinese people: A Meta-analysis / 国际外科学杂志

Objective To evaluate the association between TNFα-308 polymorphism and inflammatory bowel disease susceptibility in Chinese people.Methods The literatures about the association between TNFα-308 polymorphism and inflammatory bowel disease were collected by searching related database until July 2017.The theme words included "TNFα gene polymorphism inflammatory bowel disease" and "the free words" included "single nucleotide polymorphism nucleic acid polymorphism ulcerative colitis Crohn's disease nonspecific enteritis" were used for searching,then x2 wasapplied test to determine the combined effect heterogeneity and then analyzed the relationship between TNFα-308 polymorphism and inflammatory bowel disease disease through recessive and dominant model.Results A total of 6 references met inclusion criteria,and there were 536 patients in the case group (patients with inflammatory bowel disease) and 927 patients in the control group (normal people) healthy controls were included in this study.Recessive model OR =0.86 (95％ CI:0.30-2.46,x2 =3.02,P ＞ 0.05),Dominant model OR =1.32(95％ CI:0.95-1.84,x2 =21.58,P ＜ 0.05),After heterogeneity analysis and sensitivity test,the original research with more influence was excluded,and the final results with higher credibility were consistent with previous one.Conclusion Compared to A alleles,an individual who carries G alleles is more susceptible to ulcerative colitis,while Crohn's disease has no business with the polymorphism of TNFα.

Effect of contralateral saphenous vein bypass in the treatment of chronic femoral vein obstruction / 国际外科学杂志

Objective To study the feasibility and practicability of contralateral saphenous vein bypass in the treatment of chronic femoral vein obstruction.Methods A retrospective analysis was consisted of 33 patients who received contralateral great saphenous vein bypass during the period of June 2013 to June 2017 in the Deperrtment of Biloary Vascular Surgery of Shengjing Hospital of China Medical University.All patients after operation were followed up of 2 months deadline to August 2017 by telephone or outpatient,the follow-up content including lower limb activity after resting and subjective sensation,lower limb swelling degree and so on.The measurement data was expressed by mean standard deviation ((x) ± s),paired samples t test was used for comparison among groups.Linear correlation coefficient was used to describe the difference between ankle circumference and the time to maintain anticoagulation therapy after acute thrombosis,then we explored the effect and advantages of this surgical methods.Results Compared with the preoperative index,the activated partial thromboplastin time [(21.93 ± 3.36) svs(18.11 ±2.24)s,P＜0.05],the thrombus elastic map R value[(5.45 ±0.73)min vs(4.20 ± 0.39) min,P ＜ 0.05],the D-dimer [(3 502.79 ± 4 028.02) μg/L vs (5127.76 ± ± 4722.42) μg/L,P ＜ 0.05] and the ankle circumference [(22.23 ± 1.28) cm vs (25.38 ± 0.78) cm,P ＜ 0.05] were improved,and the prothrombin time [(12.63 ± 1.74) s vs (12.32 ± 1.14),P ＞0.05] showed no difference before and after the operation (P ＞ 0.05).With the extension of time,the effect of bypass on the treatment of lower limb edema weakened.Postoperative follow-up indicated that 33 cases of patients were unobstructed and returned to normal state,21 cases could tolerated normal physical activity and had no or mild swelling,12 cases occasional had moderate swelling while the swelling could disappear after lying down for a rest,symmetric of double lower limbs in all patients returned to acceptable degree and did not affect the clothing or appearance.Conclusion The contralateral saphenous vein bypass operation has better effect and less trauma,it can improve the lower limb edema and endogenous coagulation system of chronic obstructive iliac vein disease,and the effect is better after conservative treatment for half a year.

Mechanism of mesenchymal stromal cells in promoting islet graft revascularization / 中华肝胆外科杂志

Objective To investigate the mechanisms of mesenchymal stromal cells (MSCs) in promoting the transplanted islets neovascularization.Methods We performed co-transplantation of allogeneic islet and MSCs into non-obese diabetic (NOD) mice and the lymphocyte chimeric rate was detected by flow cytometry.The MSCs migration,transformation and secretion of cytokines were detected by immunofluorescence.Results In mice of co-combination transplantation of islet with MSCs,donor lymphocytic chimerism in graft was increased.BM-MSCs can migrate to transplanted islet,differentiate into vascular smooth muscle cells,and also secrete vascular endothelial growth factor (VEGF).Conclusions MSCs can migrate to transplanted islet and promote neovascularization.Also,it enhanced allograft immune tolerance of islet grafts via increasing donor lymphocytic chimerism.

Effect of bone mesenchymal stem cell transplantation on accelerating the vascularization surrounding transplant pancreatic islet / 器官移植

Objective To investigate whether pancreatic islet transplantation in combination with bone mesenchymal stem cells (MSC) transplantation can promote the vascularization surrounding the transplant pancreatic islet.Methods The non-obese diabetic (NOD) mice were utilized as the recipients and randomly divided into pancreatic islet transplantation combined with MSC transplantation group (co-transplantation group,n=6),pancreatic islet transplantation group(n=6),MSC transplantation group(n=6) and sham transplantation group (n=3).The variation in blood glucose level and survival rate post-transplantation of NOD mice in each group was observed.The proliferation and apoptosis of the transplant pancreatic islet in the pancreatic islet transplantation group and co-transplantation group at 1,2 and 4 weeks after pancreatic islet transplantation were analyzed by 5-ethynyl-2'-deoxyufidine (EdU) and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL).The vascular density surrounding the transplanted pancreatic islet in the pancreatic islet transplantation group and co-transplantation group at postoperative 2,4 and 8 weeks were observed under light microscope and quantitatively analyzed by histochemical and immunohistochemical staining.Results Both MSC combined with pancreatic islet transplantation and pancreatic islet transplantation significantly improved the blood glucose level and enhanced the survival rate of NOD mouse models after transplantation.In addition,it could accelerate the regeneration of pancreatic islet cells and decrease cell apoptosis.MSC combined with pancreatic islet transplantation significantly enhanced the vascular density surrounding the transplant pancreatic islet compared with pancreatic islet transplantation alone.Conclusions MSC transplantation can accelerate the vascularization surrounding the transplant pancreatic islet,increase the blood supply and protect the function and activity of the transplant pancreatic islet.

Association between VDR gene FokI polymorphism and colorectal cancer susceptibility:a meta-analysis / 实用肿瘤学杂志

Objective To discuss the relationship between FokI gene polymorphism and colorectal canc-er.Method The references that met the inclusive criteria were assessed .The extracted data were summarized in the form of tables .Data were analyzed by heterogeneity test .Meta-analysis was conducted by using fixed effects model or random effects model .Results Fifteen experimental studies were included in this study ,including 7, 859 colorectal cancer patients and 9,933 controls.The association between VDR gene FokI and colorectal cancer was expressed as the odds ratio(OR)and 95% confidence interval(CI).FokI recessive genetic model,ff versus FF+Ff,ORrecessive=1.01(95% CI=0.87~1.17,I2 =54%,P=0.91),ORdominant =0.94(95% CI=0.83~1.06,I2 =64%,P=0.30);allele model,fversus F,OR=0.98(95% CI=0.89~1.08,I2 =71%,P=0.72).In subgroup analysis,recessive genetic model,ORCaucasian race =0.95(95% CI=0.86~1.05,I2 =0%,P=0.33);ORyellow race=1.12(95%CI=0.77~1.63,I2 =72%,P=0.54).In subgroup analysis,dom-inant gene model,ORCaucasian race =0.95(95% CI=0.86~1.04,I2 =27%,P=0.29);ORyellow race =0.89(95%CI=0.65~1.22,I2 =78%,P=0.47).In subgroup analysis,allele model,ORCaucasian race=0.97 (95%CI=0.90~1.04,I2 =31%,P=0.38);ORyellow race =1(95% CI =0.79 ~1.27,I2 =82%,P=1.00).Conclusion Our results suggested that in VDR gene FokI ,F and f alleles were not obviously directly correlated with colorectal cancer .No difference was found between Asian and Caucasian .The conclusions in other populations should be further identified by extensive experimental studies .

Influence of early oral feeding after laparoscopic surgery in functional status and gastrointestinal living quality of patients with colorectal cancer / 吉林大学学报(医学版)

Objective To investigate the influence of early oral feeding (EOF)after laparoscopic surgery in the function status and gastrointestinal living quality of the patients with colorectal cancer,and to clarify the feasibility of EOF after laparoscopic surgery.Methods Sixty-three patients underwent laparoscopic surgery of colorectal cancers participated in the trial.Of these,31 patients received EOF as EOF group,received a clear liquid diet on the first postoperative day followed by a regular diet as tolerated;the other 32 patients received traditional oral feeding (TOF ) as TOF group who were fed with feeding only after the recovery of their postoperative gastrointestinal functions. The nasogastric tube was removed from all patients in both groups immediately after surgery.Self-designed EOF questionnaire data, Karnofsky Scores and Gastrointestinal Quality of Life Index (GIQLI)Scores were used to evaluate the functional status and gastrointestinal living guality of the patients. Results The using time of total parenteral nutrition (TPN),time of postoperative hospital stay,and costs after surgery in EOF group were lower than those in TOF group (P0.05),and the incidence of abdominal distension was higher than that in TOF group (P<0.05);on postoperative day 7,the albumin recovered faster in EOF group (P<0.05),and on postoperative day 4 and 7,the pro-albumin also recovered faster in EOF group (P<0.05);the patients in EOF group had a higher Karnofsky score (P<0.05)and GIQLI score compared with the patients in TOF group (P<0.05 ). Conclusion EOF after laparoscopic surgery in the patients with colorectal cancers is beneficial for rehabilitation,and it can reduce the risk of hospitalization and saving its costs;it plays an active role in protein recovery,and improves the functional status and gastrointestinal living quality of the patients.

Research on development and surgical application of surgical stapling and stitching instrument / 中国医学装备

There was almost one hundred years since surgical stapler invention to now. Using stapler (stitching instrument) in surgery has many advantages, such as stitching fast, easy to operating, few side effects and complications. It makes tumor excision surgery can’t be cut focus in past possible and improving the curative effect of the surgery. Surgical staplers also give difficult surgery and new technology strong supports. In the last ten years, for cheap price and rapid development of the technology level, domestic staplers’ market share is increasing year by year and breaking the foreign monopoly product. In open surgery, domestic stapler has progressively more than foreign brands. In endoscopy surgery, domestic staplers also have a place. In current, surgical staplers are used more and more popular in the domestic tertiary medical institutions and becoming indispensable tools in many surgeries. Surgical staplers (stitching instrument) are broadly used in esophageal reconstruction, gastrointestinal tract reconstruction, endoscopic surgery in pulmonary bulla resection, uterus resection, pancreas resection, duodenum resection

Related research on mechanical property of valve membrane in transcatheter bioprosthesis valve based on the chemical modification and cutting technology / 生物医学工程学杂志

The aim of this research is to investigate the preparation method of valve membrane in transcatheter bio- prosthetic valve, and to study the effect of chemical modification and cutting technology to tensile property and suture force property of valve membrane. We carried out a series of processes to perform the tests, such as firstly to test the crosslinking degree of valve membrane using ninhydrin method, then to test the tensile property and suture force property by using Instron's biomechanicAl testing equipment, and then to observe the collagen fiber orientation in valve membrane using Instron's biomechanical testing equipment and using field emission scanning electron microscopy. The study indicated that after the chemical modification, the crosslinking degree, tensile strength and suture force strength increasing rate of valve membrane were 93.78% ± 3. 2%, (8.24 ± 0.79) MPa, 102%, respectively. The valve membrane had a better biomechanical property and would be expected to become valve membrane in transcatheter bioprosthesis valve.

Investigation on bioactive protective function of amino acids to insulin by molecular simulation / 生物医学工程学杂志

Heat sensitive protein medicines are increasingly exhibiting their critical importance on treatment of various diseases at present. But their popularization and application meet a great challenge because of their heat instability. In the present study, insulin was taken as a heat sensitive protein medicine and amino acid as bio-protective agent in order to investigate if these amino acids can protect the insulin from losing its bioactivity due to desiccation. The experiment was performed by using replica exchange molecular simulation (REMD) method and Gromacs software with Gromos96 (53a6) force field. The REMD results indicated that these amino acids could protect the bioactive structure of insulin during desiccation. The configurations of the protected insulin were preserved very well. Those results proved that amino acid is a kind of good bioactive protective agent for the heat sensitive protein medicines.

Effect of hydroxyapatite nanoparticles on MII-stage porcine oocytes vitrification and the study of its mechanism / 生物医学工程学杂志

Nano-cryopreservation may become a new way in the next generation of cryopreservation technology. However, research using nanoparticles in oocytes vitrification has not been reported in the literature. In this study, HA nanoparticles with different diameters were added into cryoprotectant and M II-stage porcine oocytes were vitrified by Cryotop. The results showed that nanoparticles improved the survival rate of cryopreserved M II-stage porcine oocytes, but the difference between nanoparticles with different diameters of was not significant. In order to study the mechanism of nano-cryopreservation, the cooling rate of cryoprotectant was measured by ultra-fast temperature measurement system and the melting enthalpy of cryoprotectant was measured by differential scanning calorimeter (DSC). The results showed that the adding of nanoparitcles could not increase the cooling rate of cryoprotectant, but could decreases the amount of ice crystals during freezing and warming. Therefore, the mechanical injury within and outside cells might be effectively reduced.

Investigation on bioactive protection of LEA protein for insulin by molecular simulation in the low-temperature drying process / 生物医学工程学杂志

Nowadays various protein medicines are increasingly playing significant roles in the treatment of many diseases, but the bioactive structures of such kinds of protein medicines are unstable because they are heat sensitive. Therefore, it is very important to explore a protective method and to explain the protective mechanism of protein medicines. In the present research, insulin was chosen as a heat-sensitive protein medicine, and a Group 3 late embryogenesis abundant (LEA) protein was chosen as its bioactive protectant during desiccation. The results of replica exchange molecular dynamics simulation suggest that comparing with insulin without any protection, the bioactive 3D structure and secondary structure of the insulin protected by LEA protein were preserved very well. All analyzing results proved that the LEA protein was a good bioactive protectant for heat sensitive protein medicines.

Molecular simulation research on aggregation of insulin / 生物医学工程学杂志

In the present research, molecular simulation and quantum chemistry calculations were combined to investigate the thermal stability of three kinds of insulin aggregations and the effect of Zn (II) ion coordination on these aggregations. The results of molecular simulation indicated that the three insulin dimers in the same sphere closed hexamer had synergistic stability. It is the synergistic stability that enhances the structural and thermal stability of insulin, preserves its bioactivity during production, storage, and delivery of insulin formulations, and prolongs its halflife in human bodies. According to the results of quantum chemistry calculations, each Zn (II)-N (Im-insulin) bond energy can reach 73.610 kJ/mol for insulin hexamer and 79.907 kJ/mol for insulin tetramer. However, the results of Gibbs free energy changes still indicats that the coordination of zinc (II) ions is unfavorable for the formation of insulin hexamer, because the standard Gibbs free energy change of the coordinate reaction of zinc (II) ions associated with the formatting insulin hexamer is positive and increased.